Inclined Heat Exchanger with Tapered Ends

ABSTRACT

Systems and methods are disclosed that include providing a heating, ventilation, and/or air conditioning (HVAC) system with a tapered end heat exchanger (TEHE) having a first tapered end disposed at a lower end of the TEHE with respect to an incoming airflow and on the downstream face of the TEHE and having a second tapered end disposed at an upper end of the TEHE with respect to an incoming airflow and on the upstream face of the TEHE. A drain pan having louvers is disposed about the lower end of the TEHE and configured to restrict airflow through narrow portions of the first tapered end of the TEHE. A baffle is disposed about the upper end of the TEHE and configured to restrict airflow through narrow portions of the second tapered end of the TEHE.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims priority under 35 U.S.C. 119(e) to U.S. Provisional Patent Application No. 62/212,915 filed on Sep. 1, 2015 by Stephen Stewart Hancock, and entitled “Inclined Heat Exchanger with Tapered Ends,” the disclosure of which is hereby incorporated by reference in its entirety.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not applicable.

REFERENCE TO A MICROFICHE APPENDIX

Not applicable.

BACKGROUND

Heating, ventilation, and/or air conditioning (HVAC) systems may generally be used in residential and/or commercial areas for heating and/or cooling to create comfortable temperatures inside those areas. Some HVAC systems may be split-type heat pump systems that have an indoor and outdoor unit and are capable of cooling a comfort zone by operating in a cooling mode for transferring heat from a comfort zone to an ambient zone using a refrigeration cycle and also generally capable of reversing the direction of refrigerant flow through the components of the HVAC system so that heat is transferred from the ambient zone to the comfort zone, thereby heating the comfort zone. Such split type heat pump systems commonly use an inclined heat exchanger as the indoor heat exchanger due to characteristics such as efficient performance, compact size, and cost effectiveness.

SUMMARY

In some embodiments of the disclosure, a heat exchanger is disclosed as comprising: an upstream face and a downstream face; a plurality of tubes arranged in a plurality of rows; a plurality of fins disposed along the tubes; and at least one tapered end disposed on the heat exchanger, wherein the tapered end is closer to being perpendicular to a primary incoming airflow direction than at least one of the upstream face and the downstream face of the heat exchanger.

In other embodiments of the disclosure, a heating, ventilation, and/or air conditioning (HVAC) system is disclosed as comprising: a heat exchanger comprising: an upstream face and a downstream face; a plurality of tubes arranged in a plurality of rows; a plurality of fins disposed along the tubes; and at least one tapered end disposed on the heat exchanger, wherein the tapered end is closer to being perpendicular to a primary incoming airflow direction than at least one of the upstream face and the downstream face of the heat exchanger.

In other embodiments of the disclosure, a method of operating a heating, ventilation, and/or air conditioning (HVAC) system is disclosed as comprising: providing at least one heat exchanger comprising an upstream face, a downstream face, and at least one tapered end in an HVAC system; orienting the tapered end closer to perpendicular to a primary incoming airflow direction than at least one of the upstream face and the downstream face of the heat exchanger; operating the HVAC system in at least one of a cooling mode and a heating mode; restricting an airflow through the at least one tapered end of the heat exchanger; and exchanging heat between the airflow and a refrigerant carried by the at least one heat exchanger.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the present disclosure and the advantages thereof, reference is now made to the following brief description, taken in connection with the accompanying drawings and detailed description:

FIG. 1 is a schematic diagram of an HVAC system according to an embodiment of the disclosure;

FIG. 2 is a schematic diagram of a tapered end heat exchanger (TEHE) according to an embodiment of the disclosure;

FIG. 3 is a schematic diagram of a plurality of tapered end heat exchangers (TEHE's) of FIG. 2 configured as an A-coil heat exchanger according to an embodiment of the disclosure;

FIG. 4 is a schematic diagram of a plurality of tapered end heat exchangers (TEHE's) of FIG. 2 configured as a V-coil heat exchanger according to an embodiment of the disclosure; and

FIG. 5 is a flowchart of a method of operating an HVAC system according to an embodiment of the disclosure.

DETAILED DESCRIPTION

In some cases, it may be desirable to provide a tapered end heat exchanger (TEHE) in an indoor unit of an HVAC system. For instance, the performance of traditional style heat exchangers is often diminished due to poor airflow characteristics to some parts of the heat exchanger, restricted airflow passing through the heat exchanger, and/or portions of the heat exchanger that are disposed in the airflow exhaust path of other portions of the heat exchanger. By providing a tapered end heat exchanger in the indoor unit of an HVAC system, the heat transfer efficiency of the tapered end heat exchanger, the indoor unit, and/or the HVAC system may be improved over traditional style rectangular and prior tapered-end heat exchangers since the tapered ends of the tapered end heat exchanger, the configuration of the tubes of the tapered end heat exchanger, the configuration of a drain pan of the tapered end heat exchanger, and/or the configuration of a top air baffle of the tapered end heat exchanger may provide an increased airflow to portions of the tapered end heat exchanger, provide a reduced pressure drop and/or increased airflow through portions of the tapered end heat exchanger, and/or provide fewer portions of the tapered end heat exchanger disposed in the airflow exhaust path of other portions of the tapered end heat exchanger.

Referring now to FIG. 1, a schematic diagram of an HVAC system 100 is shown according to an embodiment of the disclosure. Most generally, HVAC system 100 comprises a heat pump system that may be selectively operated to implement one or more substantially closed thermodynamic refrigeration cycles to provide a cooling functionality (hereinafter “cooling mode”) and/or a heating functionality (hereinafter “heating mode”). The HVAC system 100, configured as a heat pump system, generally comprises an indoor unit 102, an outdoor unit 104, and a system controller 106 that may generally control operation of the indoor unit 102 and/or the outdoor unit 104.

Indoor unit 102 generally comprises an indoor air handling unit comprising an indoor heat exchanger 108, an indoor fan 110, an indoor metering device 112, and an indoor controller 124. The indoor heat exchanger 108 may generally be configured to promote heat exchange between refrigerant carried within internal tubing of the indoor heat exchanger 108 and an airflow that may contact the indoor heat exchanger 108 but that is segregated from the refrigerant. In some embodiments, the indoor heat exchanger 108 may comprise a plate-fin heat exchanger. However, in other embodiments, indoor heat exchanger 108 may comprise a microchannel heat exchanger and/or any other suitable type of heat exchanger.

The indoor fan 110 may generally comprise a centrifugal blower comprising a blower housing, a blower impeller at least partially disposed within the blower housing, and a blower motor configured to selectively rotate the blower impeller. The indoor fan 110 may generally be configured to provide airflow through the indoor unit 102 and/or the indoor heat exchanger 108 to promote heat transfer between the airflow and a refrigerant flowing through the indoor heat exchanger 108. The indoor fan 110 may also be configured to deliver temperature-conditioned air from the indoor unit 102 to one or more areas and/or zones of a climate controlled structure. The indoor fan 110 may generally comprise a mixed-flow fan and/or any other suitable type of fan. The indoor fan 110 may generally be configured as a modulating and/or variable speed fan capable of being operated at many speeds over one or more ranges of speeds. In other embodiments, the indoor fan 110 may be configured as a multiple speed fan capable of being operated at a plurality of operating speeds by selectively electrically powering different ones of multiple electromagnetic windings of a motor of the indoor fan 110. In yet other embodiments, however, the indoor fan 110 may be a single speed fan.

The indoor metering device 112 may generally comprise an electronically-controlled motor-driven electronic expansion valve (EEV). In some embodiments, however, the indoor metering device 112 may comprise a thermostatic expansion valve, a capillary tube assembly, and/or any other suitable metering device. In some embodiments, while the indoor metering device 112 may be configured to meter the volume and/or flow rate of refrigerant through the indoor metering device 112, the indoor metering device 112 may also comprise and/or be associated with a refrigerant check valve and/or refrigerant bypass configuration when the direction of refrigerant flow through the indoor metering device 112 is such that the indoor metering device 112 is not intended to meter or otherwise substantially restrict flow of the refrigerant through the indoor metering device 112.

Outdoor unit 104 generally comprises an outdoor heat exchanger 114, a compressor 116, an outdoor fan 118, an outdoor metering device 120, a reversing valve 122, and an outdoor controller 126. In some embodiments, the outdoor unit 104 may also comprise a plurality of temperature sensors for measuring the temperature of the outdoor heat exchanger 114, the compressor 116, and/or the outdoor ambient temperature. The outdoor heat exchanger 114 may generally be configured to promote heat transfer between a refrigerant carried within internal passages of the outdoor heat exchanger 114 and an airflow that contacts the outdoor heat exchanger 114 but that is segregated from the refrigerant. In some embodiments, outdoor heat exchanger 114 may comprise a plate-fin heat exchanger. However, in other embodiments, outdoor heat exchanger 114 may comprise a spine-fin heat exchanger, a microchannel heat exchanger, or any other suitable type of heat exchanger.

The compressor 116 may generally comprise a variable speed scroll-type compressor that may generally be configured to selectively pump refrigerant at a plurality of mass flow rates through the indoor unit 102, the outdoor unit 104, and/or between the indoor unit 102 and the outdoor unit 104. In some embodiments, the compressor 116 may comprise a rotary type compressor configured to selectively pump refrigerant at a plurality of mass flow rates. In alternative embodiments, however, the compressor 116 may comprise a modulating compressor that is capable of operation over a plurality of speed ranges, a reciprocating-type compressor, a single speed compressor, and/or any other suitable refrigerant compressor and/or refrigerant pump. In some embodiments, the compressor 116 may be controlled by a compressor drive controller 144, also referred to as a compressor drive and/or a compressor drive system.

The outdoor fan 118 may generally comprise an axial fan comprising a fan blade assembly and fan motor configured to selectively rotate the fan blade assembly. The outdoor fan 118 may generally be configured to provide airflow through the outdoor unit 104 and/or the outdoor heat exchanger 114 to promote heat transfer between the airflow and a refrigerant flowing through the indoor heat exchanger 108. The outdoor fan 118 may generally be configured as a modulating and/or variable speed fan capable of being operated at a plurality of speeds over a plurality of speed ranges. In other embodiments, the outdoor fan 118 may comprise a mixed-flow fan, a centrifugal blower, and/or any other suitable type of fan and/or blower, such as a multiple speed fan capable of being operated at a plurality of operating speeds by selectively electrically powering different multiple electromagnetic windings of a motor of the outdoor fan 118. In yet other embodiments, the outdoor fan 118 may be a single speed fan. Further, in other embodiments, however, the outdoor fan 118 may comprise a mixed-flow fan, a centrifugal blower, and/or any other suitable type of fan and/or blower.

The outdoor metering device 120 may generally comprise a thermostatic expansion valve. In some embodiments, however, the outdoor metering device 120 may comprise an electronically-controlled motor driven EEV similar to indoor metering device 112, a capillary tube assembly, and/or any other suitable metering device. In some embodiments, while the outdoor metering device 120 may be configured to meter the volume and/or flow rate of refrigerant through the outdoor metering device 120, the outdoor metering device 120 may also comprise and/or be associated with a refrigerant check valve and/or refrigerant bypass configuration when the direction of refrigerant flow through the outdoor metering device 120 is such that the outdoor metering device 120 is not intended to meter or otherwise substantially restrict flow of the refrigerant through the outdoor metering device 120.

The reversing valve 122 may generally comprise a four-way reversing valve. The reversing valve 122 may also comprise an electrical solenoid, relay, and/or other device configured to selectively move a component of the reversing valve 122 between operational positions to alter the flowpath of refrigerant through the reversing valve 122 and consequently the HVAC system 100. Additionally, the reversing valve 122 may also be selectively controlled by the system controller 106 and/or an outdoor controller 126.

The system controller 106 may generally be configured to selectively communicate with an indoor controller 124 of the indoor unit 102, an outdoor controller 126 of the outdoor unit 104 and/or other components of the HVAC system 100. In some embodiments, the system controller 106 may be configured to control operation of the indoor unit 102 and/or the outdoor unit 104. In some embodiments, the system controller 106 may be configured to monitor and/or communicate with a plurality of temperature sensors associated with components of the indoor unit 102, the outdoor unit 104, and/or the ambient outdoor temperature. Additionally, in some embodiments, the system controller 106 may comprise a temperature sensor and/or may further be configured to control heating and/or cooling of zones associated with the HVAC system 100. In other embodiments, however, the system controller 106 may be configured as a thermostat for controlling the supply of conditioned air to zones associated with the HVAC system 100.

The system controller 106 may also generally comprise a touchscreen interface for displaying information and for receiving user inputs. The system controller 106 may display information related to the operation of the HVAC system 100 and may receive user inputs related to operation of the HVAC system 100. However, the system controller 106 may further be operable to display information and receive user inputs tangentially and/or unrelated to operation of the HVAC system 100. In some embodiments, however, the system controller 106 may not comprise a display and may derive all information from inputs from remote sensors and remote configuration tools.

In some embodiments, the system controller 106 may be configured for selective bidirectional communication over a communication bus 128. In some embodiments, portions of the communication bus 128 may comprise a three-wire connection suitable for communicating messages between the system controller 106 and one or more of the HVAC system 100 components configured for interfacing with the communication bus 128. Still further, the system controller 106 may be configured to selectively communicate with HVAC system 100 components and/or any other device 130 via a communication network 132. In some embodiments, the communication network 132 may comprise a telephone network, and the other device 130 may comprise a telephone. In some embodiments, the communication network 132 may comprise the Internet, and the other device 130 may comprise a smartphone and/or other Internet-enabled mobile telecommunication device. In other embodiments, the communication network 132 may also comprise a remote server.

The indoor controller 124 may be carried by the indoor unit 102 and may generally be configured to receive information inputs, transmit information outputs, and/or otherwise communicate with the system controller 106, the outdoor controller 126, and/or any other device 130 via the communication bus 128 and/or any other suitable medium of communication. In some embodiments, the indoor controller 124 may be configured to communicate with an indoor personality module 134 that may comprise information related to the identification and/or operation of the indoor unit 102. In some embodiments, the indoor controller 124 may be configured to receive information related to a speed of the indoor fan 110, transmit a control output to an electric heat relay, transmit information regarding an indoor fan 110 volumetric flow-rate, communicate with and/or otherwise affect control over an air cleaner 136, and communicate with an indoor EEV controller 138. In some embodiments, the indoor controller 124 may be configured to communicate with an indoor fan controller 142 and/or otherwise affect control over operation of the indoor fan 110. In some embodiments, the indoor personality module 134 may comprise information related to the identification and/or operation of the indoor unit 102 and/or a position of the outdoor metering device 120.

The indoor EEV controller 138 may be configured to receive information regarding temperatures and/or pressures of the refrigerant in the indoor unit 102. More specifically, the indoor EEV controller 138 may be configured to receive information regarding temperatures and pressures of refrigerant entering, exiting, and/or within the indoor heat exchanger 108. Further, the indoor EEV controller 138 may be configured to communicate with the indoor metering device 112 and/or otherwise affect control over the indoor metering device 112. The indoor EEV controller 138 may also be configured to communicate with the outdoor metering device 120 and/or otherwise affect control over the outdoor metering device 120.

The outdoor controller 126 may be carried by the outdoor unit 104 and may be configured to receive information inputs, transmit information outputs, and/or otherwise communicate with the system controller 106, the indoor controller 124, and/or any other device via the communication bus 128 and/or any other suitable medium of communication. In some embodiments, the outdoor controller 126 may be configured to communicate with an outdoor personality module 140 that may comprise information related to the identification and/or operation of the outdoor unit 104. In some embodiments, the outdoor controller 126 may be configured to receive information related to an ambient temperature associated with the outdoor unit 104, information related to a temperature of the outdoor heat exchanger 114, and/or information related to refrigerant temperatures and/or pressures of refrigerant entering, exiting, and/or within the outdoor heat exchanger 114 and/or the compressor 116. In some embodiments, the outdoor controller 126 may be configured to transmit information related to monitoring, communicating with, and/or otherwise affecting control over the compressor 116, the outdoor fan 118, a solenoid of the reversing valve 122, a relay associated with adjusting and/or monitoring a refrigerant charge of the HVAC system 100, a position of the indoor metering device 112, and/or a position of the outdoor metering device 120. The outdoor controller 126 may further be configured to communicate with and/or control a compressor drive controller 144 that is configured to electrically power and/or control the compressor 116.

The HVAC system 100 is shown configured for operating in a so-called heating mode in which heat may generally be absorbed by refrigerant at the outdoor heat exchanger 114 and rejected from the refrigerant at the indoor heat exchanger 108. Starting at the compressor 116, the compressor 116 may be operated to compress refrigerant and pump the relatively high temperature and high pressure compressed refrigerant through the reversing valve 122 and to the indoor heat exchanger 108, where the refrigerant may transfer heat to an airflow that is passed through and/or into contact with the indoor heat exchanger 108 by the indoor fan 110. After exiting the indoor heat exchanger 108, the refrigerant may flow through and/or bypass the indoor metering device 112, such that refrigerant flow is not substantially restricted by the indoor metering device 112. Refrigerant generally exits the indoor metering device 112 and flows to the outdoor metering device 120, which may meter the flow of refrigerant through the outdoor metering device 120, such that the refrigerant downstream of the outdoor metering device 120 is at a lower pressure than the refrigerant upstream of the outdoor metering device 120. From the outdoor metering device 120, the refrigerant may enter the outdoor heat exchanger 114. As the refrigerant is passed through the outdoor heat exchanger 114, heat may be transferred to the refrigerant from an airflow that is passed through and/or into contact with the outdoor heat exchanger 114 by the outdoor fan 118. Refrigerant leaving the outdoor heat exchanger 114 may flow to the reversing valve 122, where the reversing valve 122 may be selectively configured to divert the refrigerant back to the compressor 116, where the refrigeration cycle may begin again.

Alternatively, to operate the HVAC system 100 in a so-called cooling mode, most generally, the roles of the indoor heat exchanger 108 and the outdoor heat exchanger 114 are reversed as compared to their operation in the above-described heating mode. For example, the reversing valve 122 may be controlled to alter the flow path of the refrigerant from the compressor 116 to outdoor heat exchanger 114 first and then to the indoor heat exchanger 108, the indoor metering device 112 may be enabled, and the outdoor metering device 120 may be disabled and/or bypassed. In cooling mode, heat may generally be absorbed by refrigerant at the indoor heat exchanger 108 and rejected by the refrigerant at the outdoor heat exchanger 114. As the refrigerant is passed through the indoor heat exchanger 108, the indoor fan 110 may be operated to move air into contact with the indoor heat exchanger 108, thereby transferring heat to the refrigerant from the air surrounding the indoor heat exchanger 108. Additionally, as refrigerant is passed through the outdoor heat exchanger 114, the outdoor fan 118 may be operated to move air into contact with the outdoor heat exchanger 114, thereby transferring heat from the refrigerant to the air surrounding the outdoor heat exchanger 114.

Referring now to FIG. 2, a schematic diagram of a tapered end heat exchanger (TEHE) 200 is shown according to an embodiment of the disclosure. The TEHE 200 may generally be configured as and/or employed as the indoor heat exchanger 108 of FIG. 1 and disposed in the indoor unit 102 of HVAC system 100. The TEHE 200 generally comprises a plurality of tubes 202 arranged in a plurality of rows 204, 206, 208 and disposed longitudinally through a plurality of adjacently disposed fins 210, a drain pan 212, and a baffle 216. Most generally, in this embodiment, the arrangement of the tubes 202 and the fins 210 give the TEHE 200 a shape that includes an upstream face 218, a downstream face 220 that is substantially parallel to the upstream face 218, a first tapered end 222 that forms an angle 232 with the upstream face 218, a second tapered end 224 that forms an angle 234 with the downstream face 220, a lower end 226 that is substantially orthogonal to each of the faces 218, 220 and disposed between the downstream face 220 and the first tapered end 222, and an upper end 228 that is also substantially orthogonal to each of the faces 218, 220 and disposed between the upstream face 218 and the second tapered end 224. In some embodiments, the upstream face 218 and the downstream face 220 may be not be substantially parallel to one another, and/or the lower end 226 and/or the upper end 228 may not be orthogonal to the upstream face 218 and/or the downstream face 220.

The plurality of longitudinally finned tubes 202 and/or fins 210 are generally configured to carry a refrigerant, gas, liquid, and/or other suitable heat transfer medium configured to exchange heat with an airflow 230 passing between adjacent tubes 202 and/or adjacent fins 210. The tubes 202 and/or the fins 210 may generally be constructed of copper, stainless steel, aluminum, and/or another suitable material suitable for promoting heat transfer between the heat exchange medium carried within the tubes 202 and the airflow 230. In some embodiments, the tubes 202 may extend through and beyond a fin 210 located at each end of the TEHE 200 and be joined in fluid communication with another tube 202 and/or plurality of tubes 202 by a hairpin joint and/or U-joint to form the fluid circuit through the TEHE 200. However, in other embodiments, the tubes 202 may be arranged in a plurality of parallel flowpaths and connected at each end of the TEHE 200 by a header and/or plurality of header to form the fluid circuit through the TEHE 200.

The plurality of longitudinally finned tubes 202 are generally arranged in a plurality of rows 204, 206, 208. The first row 204 of tubes 202 represents a row of tubes 202 that directly receives the airflow 230 coming from the primary incoming airflow direction 236 without first contacting another tube 202 not in the first row 204 of the TEHE 200. The first row 204 of tubes may generally extend along the upstream face 218 and the first tapered end 222 of the TEHE 200. The second row 206 of tubes 202 represents a row of tubes 202 disposed downstream from the first row 204 of tubes 202 with respect to the airflow 230 through the TEHE 230 that receives the airflow 230 after passing between and/or contacting adjacently located tubes 202 in the first row 204. The third row 208 of tubes 202 represents a row of tubes 202 disposed downstream from the second row 206 of tubes 202 with respect to the airflow 230 through the TEHE 230 that receives the airflow 230 after passing between and/or contacting adjacently located tubes 202 in the second row 206. Additionally, while the TEHE 200 is depicted as comprising three rows, in some embodiments, the TEHE 200 may comprise as few as two rows or any number of additional rows as a result of the size and/or other design criteria of the TEHE 200.

As stated, the first tapered end 222 and the second tapered end 224 generally form angles 232, 234 with the upstream face 218 and the downstream face 220, respectively. Accordingly, the angle formed between the first tapered end 222 and the adjacently located upstream face 218 may be referred to as the angle 232 of the first tapered end 222, and the angle formed between the second tapered end 224 and the adjacently located downstream face 220 may be referred to as the angle 234 of the second tapered end 224. Additionally, the tapered ends 222, 224 are oriented so that each tapered end 222, 224 is closer to being perpendicular to a primary incoming airflow direction 236 than the respective faces 218, 220 that the tapered ends 222, 224 form an angle with. In some embodiments, the first tapered end 222 and the second tapered end 224 may comprise substantially similar angles 232, 234. However, in other embodiments, the first tapered end 222 and the second tapered end 224 may comprise different angles 232, 234. In some embodiments, the angles 232, 234 may depend on the number of tubes 202 in each of the first row 204, second row 206, and third row 208. In some embodiments, the angles 232, 234 may be at least about 10 degrees, at least about 15 degrees, at least about 20 degrees, at least about 25 degrees, at least about 30 degrees, at least about 35 degrees, at least about 40 degrees, at least about 45 degrees, and/or at least about 50 degrees.

As compared to a traditional style rectangular and prior tapered-end heat exchanger, the tapered ends 222, 224 of the TEHE 200 allow more tubes 202 to be disposed in the first row 204. This is important because the temperature differential between the airflow 230 and the refrigerant carried within the first row 204 of tubes 202 is higher than between the airflow 230 and any other row of tubes 202. Thus, the first row 204 of tubes has a higher heat transfer efficiency than subsequent downstream rows 206, 208. As a result of an increased number of first row 204 tubes 202, more tubes 202 may be disposed in the second row 206, and fewer tubes may be disposed in the third row 208 as compared to a traditional style heat exchanger. Accordingly, by providing more tubes 202 in the first row 204, the number of tubes 202 in the downstream exhaust flow path of upstream tubes 202, the TEHE 200 provides an increased efficiency over a traditional style heat exchanger. For example, in this embodiment, the first row 204 comprises twenty tubes 202, the second row 206 comprises sixteen tubes 202, and the third row 208 comprises twelve tubes 202. Because tubes 202 disposed downstream from other tubes may experience about a 20% heat transfer efficiency loss with respect to the upstream row of tubes 202, the efficiency of the TEHE 200 may be calculated by multiplying the number of tubes 202 by the efficiency of the respective row that the tubes 202 are disposed in. Thus, in this embodiment, TEHE 200 comprises an efficiency of 20(1.0)+16(0.8)+12(0.64)=40.48. In contrast, a similar size traditional heat exchanger may comprise fifteen first row tubes, fourteen second row tubes, and fourteen third row tubes. Thus, the efficiency of a traditional style heat exchanger may be 15(1.0)+14(0.8)+14(0.64)=35.16.

Furthermore, traditional style rectangular and prior tapered-end heat exchangers suffer from a high pressure drop at the upper and the lower ends of the heat exchanger. The tapered ends 222, 224 of the TEHE 200 however have a fewer number of tubes 202 and thus may provide less resistance to the airflow 230 passing between the tubes 202 and/or the fins 210 disposed within the tapered end 222, 224 sections. Accordingly, the TEHE 200 may experience a reduced pressure drop through the tapered ends 222, 224 of the TEHE 200 as compared to a traditional style heat exchanger. However, it is well known that excessive airflow through a heat exchanger may reduce the efficiency. To prevent excessive airflow through the TEHE 200, the TEHE 200 comprises a drain pan 212 disposed at the lower end 226 of the TEHE 200 and a baffle 216 disposed at the upper end 228 of the TEHE 200.

The drain pan 212 is disposed about the lower end 226 of the TEHE 200. The drain pan 212 may generally extend along the first tapered end 222 and form a concavity 213 in the lower portion of the drain pan 212 that extends around the lower end 226 of the TEHE 200 and vertically along the downstream face 220. The concavity may generally be configured to catch and/or receive condensate that may form on the tubes 202 and/or the fins 210. In some embodiments, the drain pan 212 may comprise a channel, tube, and/or plurality of tubes for carrying away condensate from the concavity 213 of the drain pan 212. The drain pan 212 also comprises a plurality of louvers 214, each louver 214 forming a vent 215 in the drain pan 212, disposed along the portion of the drain pan 212 that extends along the first tapered end 222. The louvers 214 may generally be configured to overlap such that condensate that falls onto an inner surface of the drain pan 212 is carried into the concavity 213 of the drain pan 212 and so that condensate does not escape through the vents 215. Additionally, the louvers 214 are also configured to allow the airflow 230 to reach the first tapered end 222 of the TEHE 200 by passing through the vents 215 and subsequently through the TEHE 200. The louvers 214 and/or the vents 215 may also regulate air flow through the narrow portions of the TEHE 200 by increasing the obstruction typically caused by a drain pan without louvers while maximizing an upstream face 218 contact area of the TEHE 200.

In some embodiments, the louvers 214 and/or the vents 215 may comprise substantially similar sizes. However, in some embodiments, the louvers 214 and/or the vents 215 may comprise different sizes to control a pressure drop through the TEHE 200 and/or restrict airflow 230 reaching the narrow portions of the first tapered end 222 of the TEHE 200. In some embodiments, a larger louver 214 may be associated with a smaller vent 215, and a smaller louver 214 may be associated with a larger vent 215. Accordingly, in some embodiments, the vents 215 disposed closer to the lower end 226 may be smaller and/or the louvers 214 disposed closer to the lower end 226 may be larger as compared with the louvers 214 and the vents 215 disposed closer to the upstream face 218 of the TEHE 200. Thus, in some embodiments, the louvers 214 may gradually decrease in size and the vents 215 may increase in size with the largest louver 214 and smallest vent being located closest to the lower end 226, and the smallest louver 214 and the largest vent 215 being located the furthest from the lower end 226. As such, the thinnest portion of the TEHE 200 that is disposed closest to the lower end 226 may receive a substantially more restricted airflow 230 as compared to thicker portions of the TEHE 200 disposed further from the lower end 226.

The baffle 216 is disposed about the upper end 228 of the TEHE 200. The baffle 216 may generally extend slightly along the second tapered end 224, around the upper end 228 of the TEHE 200, vertically along the upstream face 218 and parallel with the primary incoming airflow direction 236, and horizontally from the vertical portion to the upstream face 218. The baffle 216 may generally be disposed substantially close to each of the second tapered end 224, the upper end 228, and the upstream face 218, so that only a minimal gap exists between the baffle 216 and the adjacent fins 210 of the TEHE 200. The baffle is generally configured to restrict the airflow 230 passing through the narrow portions of the second tapered end 224 of the TEHE 200. In some embodiments, restricting the airflow 230 may control the pressure drop through the TEHE 200 and may also increase the efficiency of the TEHE 200. By providing the louvers 214 in the drain pan 212 and the baffle 216 at each respective end 226, 228 of the TEHE 200, airflow 230 is able to contact substantially all tubes 202 of the TEHE 200, thereby providing no “dead air” and/or “inactive” portions within the TEHE 200. Additionally, by restricting airflow 230 through the first tapered end 222 and the second tapered end 224 with the drain pan 212 louvers 214 and the baffle 216, respectively, the airflow 230 through the narrow portions of the TEHE 200 associated with the tapered ends 222, 224 may be controlled in order to prevent too much airflow 230 through these portions of the TEHE 200, thereby providing a more uniform airflow 230 through the TEHE 200 and preserving and/or increasing the heat transfer efficiency of the TEHE 200 over traditional style heat exchangers.

Referring now to FIG. 3, a schematic diagram of a plurality of tapered end heat exchangers (TEHE's) 200 of FIG. 2 configured as an A-coil heat exchanger 300 is shown according to an embodiment of the disclosure. It will be appreciated that the A-coil heat exchanger 300 may also be referred to as an “A-frame” heat exchanger. Additionally, in embodiments employing multiple TEHE's 200, each TEHE 200 may be referred to as a “slab.” Heat exchanger 300 comprises two TEHE 200 heat exchangers configured in an A-coil arrangement, at least one drain pan 312, and at least one baffle 316. In some embodiments, the at least one drain pan 312 of the heat exchanger 300 may comprise two separate drain pans 212 of FIG. 2. However, in other embodiments, the drain pan 312 may be a single unit and comprise other features that join two drain pans 212 of FIG. 2 together as a single, unitary drain pan. Additionally, in some embodiments, the baffle 316 may comprise a single unit that represents two baffles 216 of FIG. 2 joined together as a single unitary baffle along the vertical portion vertically that extends along the upstream face 218 and that is substantially parallel with a primary incoming airflow direction 336. However, in other embodiments, the baffle 316 may comprise two separate baffles 216 of FIG. 2 that may substantially abut one another.

Referring now to FIG. 4, a schematic diagram of a plurality of tapered end heat exchangers (TEHE's) 200 of FIG. 2 configured as a V-coil heat exchanger 400 is shown according to an embodiment of the disclosure. It will be appreciated that the V-coil heat exchanger 400 may also be referred to as a “V-frame” heat exchanger. Heat exchanger 400 comprises two TEHE 200 heat exchangers configured in a V-coil arrangement, at least one drain pan 412, and at least one baffle 416. In some embodiments, the at least one drain pan 412 of heat exchanger 400 may comprise two separate drain pans 212 of FIG. 2 that substantially abut one another along the vertical portion that extends along the downstream face 220 of the TEHE 200. In such embodiments, the drain pan 412 may comprise tubes that connect each concavity 213 in fluid communication. However, in alternative embodiments, the drain pan 412 may be a single unit that represents two drain pans 212 of FIG. 2 joined together as a single unitary drain pan along the vertical portion that extends along the downstream face 220 of the TEHE 200. In such alternative embodiments, the drain pan 412 may not comprise the vertical portion, such that the drain pan 412 comprises a single concavity that envelopes the lower end 226 of each TEHE 200 and that is configured to collect condensate. Additionally, in some embodiments, the baffle 416 may comprise two separate baffles 216 of FIG. 2. However, in other embodiments, the baffle 416 may comprise a single unit and comprise other features that join two baffles 216 of FIG. 2 together as a single, unitary baffle.

It will be appreciated that while A-frame and V-frame heat exchangers are shown, this disclosure expressly contemplates the use of other configurations of heat exchangers. For example, alternative embodiments of heat exchangers may be configured as a W-coil (“W-frame”), M-coil (“M-frame”), N-coil (“N-frame”), inverted N-Coil (“inverted N-frame”), and/or any other configured slab type heat exchanger that employs multiple TEHE's 200 of FIG. 2, multiple heat exchangers 300 of FIG. 3, and/or multiple heat exchangers 400 of FIG. 4.

Referring now to FIG. 5 is a flowchart of a method 500 of operating an HVAC system is shown according to an embodiment of the disclosure. The method 500 may begin at block 502 by providing at least one tapered end heat exchanger (TEHE) 200 in an HVAC system. In some embodiments, the TEHE 200 may be a standalone TEHE 200, heat exchanger 300, and/or heat exchanger 400. In some embodiments, the at least one TEHE 200 may be installed in the indoor unit 102 of HVAC system 100. The method 500 may continue at block 504 by operating the HVAC system in at least one of a cooling mode and a heating mode. The method may continue at block 506 by restricting an airflow through tapered end portions of the TEHE 200. In some embodiments, the airflow 230 may be restricted through a first tapered end 222 by providing louvers 214 in a drain pan 212, and the airflow 230 may be restricted through a second tapered end 224 by a baffle 216. The method 500 may conclude at block 508 by exchanging heat between the airflow and a refrigerant carried by the at least one TEHE 200. In some embodiments, the airflow may be airflow 230 generated by indoor fan 110 of HVAC system 100. Additionally, in some embodiments, the refrigerant may be carried by tubes 202 of TEHE 200.

At least one embodiment is disclosed and variations, combinations, and/or modifications of the embodiment(s) and/or features of the embodiment(s) made by a person having ordinary skill in the art are within the scope of the disclosure. Alternative embodiments that result from combining, integrating, and/or omitting features of the embodiment(s) are also within the scope of the disclosure. Where numerical ranges or limitations are expressly stated, such express ranges or limitations should be understood to include iterative ranges or limitations of like magnitude falling within the expressly stated ranges or limitations (e.g., from about 1 to about 10 includes, 2, 3, 4, etc.; greater than 0.10 includes 0.11, 0.12, 0.13, etc.). For example, whenever a numerical range with a lower limit, R₁, and an upper limit, R_(u), is disclosed, any number falling within the range is specifically disclosed. In particular, the following numbers within the range are specifically disclosed: R=R₁+k*(R_(u)−R₁), wherein k is a variable ranging from 1 percent to 100 percent with a 1 percent increment, i.e., k is 1 percent, 2 percent, 3 percent, 4 percent, 5 percent, . . . , 50 percent, 51 percent, 52 percent, . . . , 95 percent, 96 percent, 97 percent, 98 percent, 99 percent, or 100 percent. Unless otherwise stated, the term “about” shall mean plus or minus 10 percent of the subsequent value. Moreover, any numerical range defined by two R numbers as defined in the above is also specifically disclosed. Use of the term “optionally” with respect to any element of a claim means that the element is required, or alternatively, the element is not required, both alternatives being within the scope of the claim. Use of broader terms such as comprises, includes, and having should be understood to provide support for narrower terms such as consisting of, consisting essentially of, and comprised substantially of. Accordingly, the scope of protection is not limited by the description set out above but is defined by the claims that follow, that scope including all equivalents of the subject matter of the claims. Each and every claim is incorporated as further disclosure into the specification and the claims are embodiment(s) of the present invention. 

What is claimed is:
 1. A heat exchanger, comprising: an upstream face and a downstream face; a plurality of tubes arranged in a plurality of rows; a plurality of fins disposed along the tubes; and at least one tapered end disposed on the heat exchanger, wherein the tapered end is closer to being perpendicular to a primary incoming airflow direction than at least one of the upstream face and the downstream face of the heat exchanger.
 2. The heat exchanger of claim 1, wherein the tapered end is disposed on the downstream face of the heat exchanger.
 3. The heat exchanger of claim 1, wherein the tapered end is disposed on the upstream face of the heat exchanger.
 4. The heat exchanger of claim 1, wherein a first row of tubes comprises more tubes than a second row of tubes.
 5. The heat exchanger of claim 4, wherein the second row of tubes comprises more tubes than a third row of tubes.
 6. The heat exchanger of claim 2, wherein a baffle is disposed at least partially about the at least one tapered end.
 7. The heat exchanger of claim 3, wherein a drain pan is disposed at least partially about the at least one tapered end.
 8. The heat exchanger of claim 7, wherein the drain pan comprises a plurality of louvers.
 9. The heat exchanger of claim 8, wherein the plurality of louvers comprise different sizes and are configured to restrict airflow through the at least one tapered end.
 10. The heat exchanger of claim 3, further comprising: a second tapered end disposed on an upstream side of the heat exchanger.
 11. The heat exchanger of claim 10, wherein a baffle is disposed at least partially about the second tapered end of the heat exchanger.
 12. The heat exchanger of claim 11, wherein the baffle is configured to restrict airflow through the second tapered end.
 13. The heat exchanger of claim 1, further comprising: a second heat exchanger comprising at least one tapered end, wherein the heat exchanger and the second heat exchanger are configured in at least one of an A-frame arrangement and a V-frame arrangement.
 14. The heat exchanger of claim 1, further comprising: a plurality of heat exchangers, each comprising at least one tapered end, wherein the plurality of heat exchangers are configured in at least one of an N-frame arrangement, inverted N-frame arrangement, M-frame arrangement, and a W-frame arrangement.
 15. A heating, ventilation, and/or air conditioning (HVAC) system, comprising: a heat exchanger comprising: an upstream face and a downstream face; a plurality of tubes arranged in a plurality of rows; a plurality of fins disposed along the tubes; and at least one tapered end disposed on the heat exchanger, wherein the tapered end is closer to being perpendicular to a primary incoming airflow direction than at least one of the upstream face and the downstream face of the heat exchanger.
 16. The HVAC system of claim 15, wherein the at least one tapered end is disposed on the downstream face of the heat exchanger.
 17. The HVAC system of claim 15, wherein the at least one tapered end is disposed on the upstream face of the heat exchanger.
 18. The HVAC system of claim 16, wherein a baffle is disposed at least partially about the at least one tapered end.
 19. The HVAC system of claim 17, wherein a drain pan is disposed at least partially about the at least one tapered end.
 20. The HVAC system of claim 19, wherein the drain pan comprises a plurality of louvers.
 21. The HVAC system of claim 20, wherein the plurality of louvers comprise different sizes and are configured to restrict airflow through the at least one tapered end.
 22. The HVAC system of claim 17, further comprising: a second tapered end disposed on an upstream face of the heat exchanger, wherein a baffle is disposed at least partially about an upper end of the heat exchanger and configured to restrict airflow through the second tapered end.
 23. The HVAC system of claim 15, further comprising: a second heat exchanger comprising at least one tapered end, wherein the heat exchanger and the second heat exchanger are configured in at least one of an A-frame arrangement and a V-frame arrangement.
 24. The HVAC system of claim 1, further comprising: a plurality of heat exchangers, each comprising at least one tapered end, wherein the plurality of heat exchangers are configured in at least one of an N-frame arrangement, inverted N-frame arrangement, M-frame arrangement, and a W-frame arrangement.
 25. The HVAC system of claim 11, wherein the heat exchanger is disposed in an indoor unit of the HVAC system.
 26. A method of operating a heating, ventilation, and/or air conditioning (HVAC) system, comprising: providing at least one heat exchanger comprising an upstream face, a downstream face, and at least one tapered end in an HVAC system; orienting the tapered end closer to perpendicular to a primary incoming airflow direction than at least one of the upstream face and the downstream face of the heat exchanger; operating the HVAC system in at least one of a cooling mode and a heating mode; restricting an airflow through the at least one tapered end of the heat exchanger; and exchanging heat between the airflow and a refrigerant carried by the at least one heat exchanger.
 27. The method of claim 26, wherein the at least one tapered end is disposed on an upstream face of the heat exchanger, and wherein a baffle is disposed at least partially about the at least one tapered end.
 28. The method of claim 26, wherein the at least one tapered end is disposed on an downstream face of the heat exchanger, and wherein a drain pan is disposed at least partially about the at least one tapered end.
 29. The method of claim 27, wherein the restricting an airflow through the at least one tapered end of the heat exchanger is accomplished by disposing a baffle at least partially about the at least one tapered end.
 30. The method of claim 28, wherein the restricting an airflow through the at least one tapered end of the heat exchanger is accomplished by disposing a drain pan comprising a plurality of louvers at least partially about the at least one tapered end. 